Test and measurement instruments, such as an oscilloscope, can capture portions of a waveform, or other data, when certain events occur, which is referred to as triggering. The test and measurement instruments, however, must be put into a triggering state to begin triggering on an event. The triggering event may be an event occurring in a signal-under-test (SUT) from a device-under-test (DUT), or the event may be an event occurring in another signal. State of the art real-time oscilloscopes typically include manually selecting a user-interface (UI) control, pushing a physical button, or sending a programmable interface (PI) command from a control computer, to begin triggering. Once placed in a triggering state, various oscilloscope trigger methods may then capture digitized waveforms representing the signals-under-test. The trigger methods may be simple (Edge, Glitch, Pulse-Width, etc.) or complex A-to-B sequence triggers, e.g., Edge followed by Pulse Width after a certain time or number of B-Events. Additional trigger qualifications such as Reset Events or Logic Qualification Events may apply. However, these trigger methods only capture waveforms after the oscilloscope is in a triggering state.
Manually setting the oscilloscope in a trigger state may be ineffective because the manual input is unrelated to real-time events occurring in the signals-under-test, resulting in crude selectivity of captured waveforms. Setting oscilloscopes in a trigger state by PI commands may also be ineffective for the same reasons, or because the computer-to-scope communication channel is too slow to selectively capture real-time signal events of interest. Furthermore, complex trigger methods alone may not be selective enough to capture events of interest.
This disclosure addresses these and other deficiencies of the prior art.